Wow, quite a few issues.

(1) plugin-container.exe

Usually issues with plugin-container.exe are actually issues with the most commonly used plugin, the Flash player. Have you seen any indication of Flash problems, or done any Flash troubleshooting?

(2) Bookmarks

What changed that makes it hard to find bookmarks? What's missing?

(3) Downloads

This is a new design in Firefox 20. For a complete write-up, see: Where to find and manage downloaded files in Firefox.

If you can't get used to it, or don't want to get used to it, there is a way to revert back to the old download manager. See: Got new version, want to go back to previous download box.

I have not had any problems with the flash player be itself, only in the browser since ver 19.

I used to go to the data application under mozilla profiles to save a copy of my bookmarks or even load it into WordPerfect to view. The format changed sometime ago but I could still bring them up in Frontpage on a saved copy. I sometimes like to copy the links when I am writing a school paper it is easiler than bringing up the web page.

If I go back to ver 20 I will also be going backing to the old download.

If you check the following page, are there any crash reports that seem to coincide with the plugin-container.exe episodes?

about:crashes {type or paste into the address bar and press Enter}

For your bookmarks, perhaps you could use the Export feature to create that reference file in HTML format. The native places.sqlite database and the .json-format backups are not very eyeball-friendly.

To export bookmarks in recent versions of Firefox, see this article: Export Firefox bookmarks to an HTML file to back up or transfer bookmarks.

Edit: I think there might be an add-on to automate that export. Perhaps you had that before?

thanks for the bookmark fix.

19 & 20 do not crash they hang.

Go to the Mozilla Firefox program folder, find plugin-hang-ui.exe and delete it or simply search for plugin-hang-ui.exe and delete it that way. Your problem will be solved.

In reference to Battlewagon's suggestion about deleting a Firefox program file, there is a less drastic way to disable the message about whether you want to terminate the plugin or wait for it to come back to life. That is described in this article: How to Disable Plugin Hang UI in Firefox 20.

You can make Firefox create an automatic HTML backup (bookmarks.html) when you exit Firefox if you set the browser.bookmarks.autoExportHTML pref to true on the about:config page.

• http://kb.mozillazine.org/browser.bookmarks.autoExportHTML
• http://kb.mozillazine.org/about:config

That backup is created by default in the profile folder as bookmarks.html, but you can set the file name and path via the browser.bookmarks.file pref on the about:config page.

• http://kb.mozillazine.org/browser.bookmarks.file

The browser.bookmarks.file pref doesn't exist by default and you need to create a new String pref with the name browser.bookmarks.file and set the value to the full path of the backup bookmarks file (you need to escape backslashes as \\).

Don't be distracted by Flash. The same thing happens with Silverlight. The design is broken and Mozilla needs to figure it out. It's pathetic.

Personally I don't think their developers are good enough to fix it.

Hi gnostic, if you know better how to eliminate problems with plugins, please help. It's open source and volunteers are welcome.

I solved the problem with plugin container using 50-90% of CPU by disabling all plugins except Java. Now I add them one at a time if a page says it needs one. So far I've enabled Flash and Acrobat without problems so I don't believe the problem I had was anything to do with incompatibilities with the Flash plugin though others' experience looks different.

Maybe there are two problems, one caused by Flash on some systems and one caused by ?Silverlight ?Realplayer ?Quicktime.

This is the only thing that worked! Tried every other possible solution on 5-6 different threads, weither it was about:config changes, plugin disabling, software updating... none of it worked to stop Flash or shockwave flash from bogging down plugin-container.exe to the point of......... well you all know! Downgrading to 18.0.2 AND using flashblock stops the hangs and cpu hogging. Now i will admit to a larger VM being used, however, it at least loads! Flashblock is a preference because my computer is OLD (512mb ram, win xp, gforce3 grapics card etc. lol :p) and this allows most pages to load much faster for me. If there is a video I want to view on the page and not some dumb ad or grapic, one simple click and its veiwable. Thanks again for this! *Stops banging head on desk *

This is rather an old thread relating to Firefox 19 and 20 whereas the current Release is now Firefox 24.

There have been changes recently and further changes in Firefox 25 about how plugins are handled. As this is an old thread I will lock it.

Please note it is NOT advisable to use old, unsupported, and insecure versions of Firefox that increases risks to your personal data and your system.

• see Install an older version of Firefox
• and a list of potential vulnerabilities and exploits
  https://www.mozilla.org/security/known-vulnerabilities/firefox.html